A faulty Covid app puts everyone at risk | Letters

There are well-established guards against mathematical errors in other sectors, writes Sabina Ali, so why are risks being taken with public health? Plus Carol Granere on testing failures

Your article (Fault in NHS Covid app meant thousands at risk did not quarantine, 2 November) states that an oversight" from the programmers is at the source of thousands being put at risk. Why is it considered acceptable to take such risks in public health during apandemic? These failings put us in danger. There are ways of ensuring that the maths does not go wrong by using risk assessment strategies well established in other sectors.

The government declining to communicate on the number of people advised to self-isolate isn't acceptable either. There has been a clear lack of transparency from the conception of the app to its consequences. This can only lead to greater distrust from the public, jeopardising our Covid recovery.
Sabina Ali
Just Algorithms Action Group